Fix link of futures-select-macro documentation

Author: taiki-e

futures-select-macro/Cargo.toml

@@ -6,7 +6,7 @@ authors = ["Taylor Cramer <[email protected]>"]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/rust-lang-nursery/futures-rs"
 homepage = "https://rust-lang-nursery.github.io/futures-rs"
-documentation = "https://rust-lang-nursery.github.io/futures-api-docs/0.3.0-alpha.13/futures_select"
+documentation = "https://rust-lang-nursery.github.io/futures-api-docs/0.3.0-alpha.13/futures_select_macro"
 description = """
 The `select!` macro for waiting on multiple different `Future`s at once and handling the first one to complete.
 """